// Copyright (c) 2009-2014 The Bitcoin Core developers // Copyright (c) 2017 The Zcash developers // Distributed under the GPLv3 software license, see the accompanying // file COPYING or https://www.gnu.org/licenses/gpl-3.0.en.html /****************************************************************************** * Copyright © 2014-2019 The SuperNET Developers. * * * * See the AUTHORS, DEVELOPER-AGREEMENT and LICENSE files at * * the top-level directory of this distribution for the individual copyright * * holder information and the developer policies on copyright and licensing. * * * * Unless otherwise agreed in a custom licensing agreement, no part of the * * SuperNET software, including this file may be copied, modified, propagated * * or distributed except according to the terms contained in the LICENSE file * * * * Removal or modification of this copyright notice is prohibited. * * * ******************************************************************************/ #include "key.h" #include "arith_uint256.h" #include "crypto/common.h" #include "crypto/hmac_sha512.h" #include "pubkey.h" #include "random.h" #include #include static secp256k1_context* secp256k1_context_sign = NULL; /** These functions are taken from the libsecp256k1 distribution and are very ugly. */ /** * This parses a format loosely based on a DER encoding of the ECPrivateKey type from * section C.4 of SEC 1 , with the following caveats: * * * The octet-length of the SEQUENCE must be encoded as 1 or 2 octets. It is not * required to be encoded as one octet if it is less than 256, as DER would require. * * The octet-length of the SEQUENCE must not be greater than the remaining * length of the key encoding, but need not match it (i.e. the encoding may contain * junk after the encoded SEQUENCE). * * The privateKey OCTET STRING is zero-filled on the left to 32 octets. * * Anything after the encoding of the privateKey OCTET STRING is ignored, whether * or not it is validly encoded DER. * * out32 must point to an output buffer of length at least 32 bytes. */ static int ec_privkey_import_der(const secp256k1_context* ctx, unsigned char *out32, const unsigned char *privkey, size_t privkeylen) { const unsigned char *end = privkey + privkeylen; memset(out32, 0, 32); /* sequence header */ if (end - privkey < 1 || *privkey != 0x30u) { return 0; } privkey++; /* sequence length constructor */ if (end - privkey < 1 || !(*privkey & 0x80u)) { return 0; } size_t lenb = *privkey & ~0x80u; privkey++; if (lenb < 1 || lenb > 2) { return 0; } if (end - privkey < lenb) { return 0; } /* sequence length */ size_t len = privkey[lenb-1] | (lenb > 1 ? privkey[lenb-2] << 8 : 0u); privkey += lenb; if (end - privkey < len) { return 0; } /* sequence element 0: version number (=1) */ if (end - privkey < 3 || privkey[0] != 0x02u || privkey[1] != 0x01u || privkey[2] != 0x01u) { return 0; } privkey += 3; /* sequence element 1: octet string, up to 32 bytes */ if (end - privkey < 2 || privkey[0] != 0x04u) { return 0; } size_t oslen = privkey[1]; privkey += 2; if (oslen > 32 || end - privkey < oslen) { return 0; } memcpy(out32 + (32 - oslen), privkey, oslen); if (!secp256k1_ec_seckey_verify(ctx, out32)) { memset(out32, 0, 32); return 0; } return 1; } /** * This serializes to a DER encoding of the ECPrivateKey type from section C.4 of SEC 1 * . The optional parameters and publicKey fields are * included. * * privkey must point to an output buffer of length at least CKey::PRIVATE_KEY_SIZE bytes. * privkeylen must initially be set to the size of the privkey buffer. Upon return it * will be set to the number of bytes used in the buffer. * key32 must point to a 32-byte raw private key. */ static int ec_privkey_export_der(const secp256k1_context *ctx, unsigned char *privkey, size_t *privkeylen, const unsigned char *key32, int compressed) { assert(*privkeylen >= CKey::PRIVATE_KEY_SIZE); secp256k1_pubkey pubkey; size_t pubkeylen = 0; if (!secp256k1_ec_pubkey_create(ctx, &pubkey, key32)) { *privkeylen = 0; return 0; } if (compressed) { static const unsigned char begin[] = { 0x30,0x81,0xD3,0x02,0x01,0x01,0x04,0x20 }; static const unsigned char middle[] = { 0xA0,0x81,0x85,0x30,0x81,0x82,0x02,0x01,0x01,0x30,0x2C,0x06,0x07,0x2A,0x86,0x48, 0xCE,0x3D,0x01,0x01,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, 0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F,0x30,0x06,0x04,0x01,0x00,0x04,0x01,0x07,0x04, 0x21,0x02,0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0,0x62,0x95,0xCE,0x87, 0x0B,0x07,0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8, 0x17,0x98,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, 0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E, 0x8C,0xD0,0x36,0x41,0x41,0x02,0x01,0x01,0xA1,0x24,0x03,0x22,0x00 }; unsigned char *ptr = privkey; memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin); memcpy(ptr, key32, 32); ptr += 32; memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle); pubkeylen = CPubKey::COMPRESSED_PUBLIC_KEY_SIZE; secp256k1_ec_pubkey_serialize(ctx, ptr, &pubkeylen, &pubkey, SECP256K1_EC_COMPRESSED); ptr += pubkeylen; *privkeylen = ptr - privkey; assert(*privkeylen == CKey::COMPRESSED_PRIVATE_KEY_SIZE); } else { static const unsigned char begin[] = { 0x30,0x82,0x01,0x13,0x02,0x01,0x01,0x04,0x20 }; static const unsigned char middle[] = { 0xA0,0x81,0xA5,0x30,0x81,0xA2,0x02,0x01,0x01,0x30,0x2C,0x06,0x07,0x2A,0x86,0x48, 0xCE,0x3D,0x01,0x01,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, 0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F,0x30,0x06,0x04,0x01,0x00,0x04,0x01,0x07,0x04, 0x41,0x04,0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0,0x62,0x95,0xCE,0x87, 0x0B,0x07,0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8, 0x17,0x98,0x48,0x3A,0xDA,0x77,0x26,0xA3,0xC4,0x65,0x5D,0xA4,0xFB,0xFC,0x0E,0x11, 0x08,0xA8,0xFD,0x17,0xB4,0x48,0xA6,0x85,0x54,0x19,0x9C,0x47,0xD0,0x8F,0xFB,0x10, 0xD4,0xB8,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, 0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E, 0x8C,0xD0,0x36,0x41,0x41,0x02,0x01,0x01,0xA1,0x44,0x03,0x42,0x00 }; unsigned char *ptr = privkey; memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin); memcpy(ptr, key32, 32); ptr += 32; memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle); pubkeylen = CPubKey::PUBLIC_KEY_SIZE; secp256k1_ec_pubkey_serialize(ctx, ptr, &pubkeylen, &pubkey, SECP256K1_EC_UNCOMPRESSED); ptr += pubkeylen; *privkeylen = ptr - privkey; assert(*privkeylen == CKey::PRIVATE_KEY_SIZE); } return 1; } bool CKey::Check(const unsigned char *vch) { return secp256k1_ec_seckey_verify(secp256k1_context_sign, vch); } void CKey::MakeNewKey(bool fCompressedIn) { do { GetRandBytes(vch, sizeof(vch)); } while (!Check(vch)); fValid = true; fCompressed = fCompressedIn; } int32_t CKey::SetKey32(uint8_t Key32[32]) { memcpy(vch,Key32,32); fCompressed = true; if ( Check(vch) == 0 ) { fValid = false; return(-1); } else { fValid = true; return(0); } } bool CKey::SetPrivKey(const CPrivKey &privkey, bool fCompressedIn) { if (!ec_privkey_import_der(secp256k1_context_sign, (unsigned char*)begin(), &privkey[0], privkey.size())) return false; fCompressed = fCompressedIn; fValid = true; return true; } CPrivKey CKey::GetPrivKey() const { assert(fValid); CPrivKey privkey; int ret; size_t privkeylen; privkey.resize(PRIVATE_KEY_SIZE); privkeylen = PRIVATE_KEY_SIZE; ret = ec_privkey_export_der(secp256k1_context_sign, (unsigned char*)&privkey[0], &privkeylen, begin(), fCompressed ? SECP256K1_EC_COMPRESSED : SECP256K1_EC_UNCOMPRESSED); assert(ret); privkey.resize(privkeylen); return privkey; } CPubKey CKey::GetPubKey() const { assert(fValid); secp256k1_pubkey pubkey; size_t clen = CPubKey::PUBLIC_KEY_SIZE; CPubKey result; int ret = secp256k1_ec_pubkey_create(secp256k1_context_sign, &pubkey, begin()); assert(ret); secp256k1_ec_pubkey_serialize(secp256k1_context_sign, (unsigned char*)result.begin(), &clen, &pubkey, fCompressed ? SECP256K1_EC_COMPRESSED : SECP256K1_EC_UNCOMPRESSED); assert(result.size() == clen); assert(result.IsValid()); return result; } bool CKey::Sign(const uint256 &hash, std::vector& vchSig, uint32_t test_case) const { if (!fValid) return false; vchSig.resize(CPubKey::SIGNATURE_SIZE); size_t nSigLen = CPubKey::SIGNATURE_SIZE; unsigned char extra_entropy[32] = {0}; WriteLE32(extra_entropy, test_case); secp256k1_ecdsa_signature sig; int ret = secp256k1_ecdsa_sign(secp256k1_context_sign, &sig, hash.begin(), begin(), secp256k1_nonce_function_rfc6979, test_case ? extra_entropy : NULL); assert(ret); secp256k1_ecdsa_signature_serialize_der(secp256k1_context_sign, (unsigned char*)&vchSig[0], &nSigLen, &sig); vchSig.resize(nSigLen); return true; } bool CKey::VerifyPubKey(const CPubKey& pubkey) const { if (pubkey.IsCompressed() != fCompressed) { return false; } unsigned char rnd[8]; std::string str = "Zcash key verification\n"; GetRandBytes(rnd, sizeof(rnd)); uint256 hash; CHash256().Write((unsigned char*)str.data(), str.size()).Write(rnd, sizeof(rnd)).Finalize(hash.begin()); std::vector vchSig; Sign(hash, vchSig); return pubkey.Verify(hash, vchSig); } bool CKey::SignCompact(const uint256 &hash, std::vector& vchSig) const { if (!fValid) return false; vchSig.resize(CPubKey::COMPACT_SIGNATURE_SIZE); int rec = -1; secp256k1_ecdsa_recoverable_signature sig; int ret = secp256k1_ecdsa_sign_recoverable(secp256k1_context_sign, &sig, hash.begin(), begin(), secp256k1_nonce_function_rfc6979, NULL); assert(ret); secp256k1_ecdsa_recoverable_signature_serialize_compact(secp256k1_context_sign, (unsigned char*)&vchSig[1], &rec, &sig); assert(ret); assert(rec != -1); vchSig[0] = 27 + rec + (fCompressed ? 4 : 0); return true; } bool CKey::Load(CPrivKey &privkey, CPubKey &vchPubKey, bool fSkipCheck=false) { if (!ec_privkey_import_der(secp256k1_context_sign, (unsigned char*)begin(), &privkey[0], privkey.size())) return false; fCompressed = vchPubKey.IsCompressed(); fValid = true; if (fSkipCheck) return true; return VerifyPubKey(vchPubKey); } bool CKey::Derive(CKey& keyChild, ChainCode &ccChild, unsigned int nChild, const ChainCode& cc) const { assert(IsValid()); assert(IsCompressed()); unsigned char out[64]; LockObject(out); if ((nChild >> 31) == 0) { CPubKey pubkey = GetPubKey(); assert(pubkey.size() == CPubKey::COMPRESSED_PUBLIC_KEY_SIZE); BIP32Hash(cc, nChild, *pubkey.begin(), pubkey.begin()+1, out); } else { assert(size() == 32); BIP32Hash(cc, nChild, 0, begin(), out); } memcpy(ccChild.begin(), out+32, 32); memcpy((unsigned char*)keyChild.begin(), begin(), 32); bool ret = secp256k1_ec_privkey_tweak_add(secp256k1_context_sign, (unsigned char*)keyChild.begin(), out); UnlockObject(out); keyChild.fCompressed = true; keyChild.fValid = ret; return ret; } bool CExtKey::Derive(CExtKey &out, unsigned int nChild) const { out.nDepth = nDepth + 1; CKeyID id = key.GetPubKey().GetID(); memcpy(&out.vchFingerprint[0], &id, 4); out.nChild = nChild; return key.Derive(out.key, out.chaincode, nChild, chaincode); } void CExtKey::SetMaster(const unsigned char *seed, unsigned int nSeedLen) { static const unsigned char hashkey[] = {'B','i','t','c','o','i','n',' ','s','e','e','d'}; unsigned char out[64]; LockObject(out); CHMAC_SHA512(hashkey, sizeof(hashkey)).Write(seed, nSeedLen).Finalize(out); key.Set(&out[0], &out[32], true); memcpy(chaincode.begin(), &out[32], 32); UnlockObject(out); nDepth = 0; nChild = 0; memset(vchFingerprint, 0, sizeof(vchFingerprint)); } CExtPubKey CExtKey::Neuter() const { CExtPubKey ret; ret.nDepth = nDepth; memcpy(&ret.vchFingerprint[0], &vchFingerprint[0], 4); ret.nChild = nChild; ret.pubkey = key.GetPubKey(); ret.chaincode = chaincode; return ret; } void CExtKey::Encode(unsigned char code[BIP32_EXTKEY_SIZE]) const { code[0] = nDepth; memcpy(code+1, vchFingerprint, 4); code[5] = (nChild >> 24) & 0xFF; code[6] = (nChild >> 16) & 0xFF; code[7] = (nChild >> 8) & 0xFF; code[8] = (nChild >> 0) & 0xFF; memcpy(code+9, chaincode.begin(), 32); code[41] = 0; assert(key.size() == 32); memcpy(code+42, key.begin(), 32); } void CExtKey::Decode(const unsigned char code[BIP32_EXTKEY_SIZE]) { nDepth = code[0]; memcpy(vchFingerprint, code+1, 4); nChild = (code[5] << 24) | (code[6] << 16) | (code[7] << 8) | code[8]; memcpy(chaincode.begin(), code+9, 32); key.Set(code+42, code+BIP32_EXTKEY_SIZE, true); } bool ECC_InitSanityCheck() { CKey key; key.MakeNewKey(true); CPubKey pubkey = key.GetPubKey(); return key.VerifyPubKey(pubkey); } void ECC_Start() { assert(secp256k1_context_sign == NULL); secp256k1_context *ctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN); assert(ctx != NULL); { // Pass in a random blinding seed to the secp256k1 context. unsigned char seed[32]; LockObject(seed); GetRandBytes(seed, 32); bool ret = secp256k1_context_randomize(ctx, seed); assert(ret); UnlockObject(seed); } secp256k1_context_sign = ctx; } void ECC_Stop() { secp256k1_context *ctx = secp256k1_context_sign; secp256k1_context_sign = NULL; if (ctx) { secp256k1_context_destroy(ctx); } }